1. Field of the Invention
This invention relates to a wheel of an electric wheelchair and a wheelchair including a small-size battery and, more particularly, to a wheel for a wheelchair and a wheelchair provided with a motor and an input sensor for detecting an input torque to a handrim.
2. Description of the Related Art
A wheelchair includes a frame, a seat attached to the frame, wheels mounted on the frame and handrims connected to the wheels. A user seated on the seat operates the handrims, whereby the wheels rotate. In such a wheelchair, a large force is necessary to rotate the wheels by operating the handrims. For example, the user is considerably tired in the case of moving the wheelchair over a long time or moving on a hill.
Wheelchairs mounted with a battery, a motor and a J/S controller have been utilized. With such a wheelchair, a user operates the J/S controller, whereby power is supplied from the battery to the motor. The motor rotates by the power from the battery to move the wheelchair. In the wheelchair provided with the battery and the motor, fatigue in moving the wheelchair can be drastically reduced. However, in such a wheelchair, all the power necessary for movement is supplied from the motor. In such a wheelchair, the battery, having a large capacity, is mounted in preparation for a case where the motor is driven for a long time. Thus, the weight of the entire wheelchair becomes heavier and it becomes difficult to lift the wheelchair. It is, for example, difficult to lift such a wheelchair and put it into an automotive vehicle.
A wheelchair provided with small-size battery and motor are being studied to prevent the wheelchair from becoming heavier and larger in size and reduce labor necessary to operate the wheelchair. In this wheelchair, part of the power necessary for movement is supplied from the motor as a user operates the handrims. In this wheelchair, the wheelchair is moved by power supplied from the motor in addition to a force applied from the user to operate the handrims (see JPH09-575A).